Allyn, what you have stated is only partially correct. Copyright is a difficult field, without providing potentially misleading information. Erring on the side of caution is by far the most sensible way forward.
The most obvious place for Zephyr to start is with the copyright instructions that come with the design. These are not always the same for every designer or every design, so it is imperative to read what the designer has stated. Some designers will allow you to make a working copy; many will allow you to stitch the design several times for charity; none that I've ever come across will allow you to kit up and sell the design. Would the designer of Zephyr's strawberry cake allow her to stitch the design, mount it onto a bag and sell it? I don't know, and neither do you. Zephyr needs to read the copyright restrictions. If she is in doubt,
she should ASK the designer.
Can't find any copyright information on your kit or download?
This does not mean that copyright does not apply. The moment designers metaphorically put pencils to graph paper, they also create the copyright that protects that design. Does a design have to be officially registered to be copyrighted? No. Registration only strengthens the copyright in various ways, most notably allowing access to the courts for redress of violation, but registration doesn’t create the copyright. The copyright is inherent in the creative process.
You are correct that Zephyr can't claim the blue design as her own. If someone can look at the changes she has made in the design and see the work of the original artist, then copyright could be infringed. Common sense tell you that this doesn’t apply to ideas which are universal or can’t be expressed in other ways, like a bunch of flowers or a kitten. However, it does apply to the unique way a designer has interpreted the bunch of flowers or kitten, and that is what is copyrighted.
The forum has always been very careful about issues of copyright: we don't want to get into trouble, and we don't want our members to get into trouble, either. We are always happy to field questions about copyright -- the idea that "the only stupid question is one you don't ask" goes double with bells on when dealing with legal matters.
I strongly suggest that forum members head to the top of this thread and explore some of the links there. But here are some which are immediately useful:
Because this forum is registered in the UK,
this is a quick link.
And because many of you are in the US, try
this and
this (which is very readable).
And for completeness,
the Berne Convention, which is an international copyright treaty.